Drench Gun Maintenance

25 Sep, 2018

Instructions for cleaning the Vetmec 15mL Sheep Drenching Gun. Clean regularly to maintain the performance of your drenching gun. 

(click here for a printable PDF version of these instructions)

Unscrew the barrel from green piston housing & pull the barrel off the piston.

Rear Valve:

  1. Remove the valve retainer by placing a blunt tool (we use a 4mm Allen key) into the middle of the plastic inlet valve retainer and lever it out (see diagram 1 below)
  2. Remove valve & spring. Ensure it is clean and clear of any debris. Also, make sure you clean the inlet valve housing that runs back inside the piston.
    Note: the valve sits in the narrow end of the spring (as per diagram 3 below)
  3. Replace in reverse as in illustration 2. and press the valve, spring and retainer firmly back into the inlet valve housing with your thumb (see diagram 2 below)

Front valve:

  1. To get the valve assembly out, always push the valve, spring & retainer from the front of the barrel back through the brass outlet valve housing with a suitable blunt tool (We use a 4mm Allen key). See diagram 1 below.
  2. When the plastic retainer, valve & spring are freed by the above procedure, undo the retaining nut from the brass valve housing allowing it to be released from the barrel as shown in diagram 2 (below).
    Figure 3 (below) shows the assembly apart. Ensure all components are clean and free from debris or drench particles.
  3. To reassemble, reverse the procedure by first pushing the valve spring and plastic retainer back into the brass outlet valve housing and press firmly in place with your thumb (see figure 4 below). Reattach the brass outlet valve housing to the barrel with the barrel-shield and retaining nut.

Orange “O\” ring and felt washer on piston:

The Orange “O\” ring does all of the pumping work. The felt washer is there only as a lubricant storage washer. Remember this should only be oiled with a Vegetable oil eg Olive oil, Canola oil etc, NOT Mineral Oil as it will degrade the “O’ ring.

Lubricate the felt washer & “O\” ring with vegetable oil and be careful when putting the barrel back over the piston, to get the “O\” ring to sit straight and flush in its seating. Be careful not to cross-thread the barrel when screwing it back on to the handle.

Putting it back together – sheep drench gun

From left to right

  1. Nozzle
  2. Retaining Nut
  3. Barrel Shield
  4. “O\” Ring
  5. Brass Outlet Valve Housing
  6. Outlet Valve with Spring
  7. Outlet Valve Retainer (Plastic)
  8. Barrel
  9. Inlet Valve Retainer (Plastic)
  10. Inlet Valve with Spring
  11. Orange “O\”-ring
  12. Felt Lubricating Washer
  13. Piston
  14. Handle & Piston Housing

Note: a new lubricating felt washer is better put on dry, trimmed if too long and again only oiled with a Vegetable Oil.

How the gun should look assembled


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